Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 73, NWS Fort Worth, TX

April 3, 1999Grayson County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Apr 3, 1999, 5:13 AM CST for Grayson County, Texas. It was in force for 62 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 3, 1999, 5:13 AM CST (11:13 UTC)
Expired
Apr 3, 1999, 6:15 AM CST
In force
62 min
Issued by
NWS Fort Worth, TX
Area
Whole counties

County Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 131 km from the middle of the area, began a volume at 11:16 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Apr 3, 5:50 AM CSTThunderstorm Wind 56Van Alstyne, TXA trained spotter reported 60 to 70 mph winds associated with thunderstorms.
Apr 3, 5:57 AM CSTHail 0.75Van Alstyne, TX

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 11.2 hours before the alert went out and 105 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 1999-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2394 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 1999-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2394 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
781 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.6

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

Everything else NWS Fort Worth, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 3, 4:00 AM CSTSevere Thunderstorm WarningFWDTarrant45 min
Apr 3, 4:37 AM CSTSevere Thunderstorm WarningFWDCollin, Denton68 min
Apr 3, 4:43 AM CSTSevere Thunderstorm WarningFWDTarrant47 min
Apr 3, 5:31 AM CSTSevere Thunderstorm WarningFWDFannin59 min
Apr 3, 5:45 AM CSTSevere Thunderstorm WarningFWDCollin, Denton45 min
Apr 3, 6:01 AM CSTSevere Thunderstorm WarningFWDMills29 min
Apr 3, 6:13 AM CSTSevere Thunderstorm WarningFWDGrayson47 min
Apr 3, 6:28 AM CSTSevere Thunderstorm WarningFWDHamilton47 min
Apr 3, 6:49 AM CSTSevere Thunderstorm WarningFWDDenton, Grayson41 min
Apr 3, 7:05 AM CSTFlash Flood WarningFWDDenton, Grayson3 hr
Apr 3, 7:13 AM CSTSevere Thunderstorm WarningFWDHamilton32 min
Apr 3, 7:24 AM CSTSevere Thunderstorm WarningFWDParker, Tarrant51 min
Apr 3, 7:30 AM CSTSevere Thunderstorm WarningFWDErath, Hood, Somervell45 min
Apr 3, 7:51 AM CSTSevere Thunderstorm WarningFWDDenton39 min
Apr 3, 8:27 AM CSTFlash Flood WarningFWDHamilton3 hr
Apr 3, 9:18 AM CSTSevere Thunderstorm WarningFWDJohnson42 min
Apr 3, 9:42 AM CSTSevere Thunderstorm WarningFWDEllis48 min

Nearby

Severe Thunderstorm Warnings in Texas, 1999Every severe thunderstorm warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.